Cumulus Support

So, after setting up my Pro 2 Plus at the weekend we have had 2 very clear days, so I have played around with the solar settings. I initially set the settings to Sun threshold 75, Sun Min 50 and Trans factor 0.87 (after what someone else said they were using). But the clear day yesterday showed that the Trans factor was a bit high, so throughout the afternoon I played with it a bit, and at the end of the day decided 0.83 seemed to fit quite well. So today was another very clear sunny day, and I have attached a pic of the outcome. The 2 lines a very close to each other apart from them starting to skew a bit after about 11am, until mid afternoon (and the bit before 8am, but that's where the sun is cut off from the sensor by a roof). I could try dropping the trans slightly to get a closer fit around early afternoon, but I would expect it to then be too low in the morning and afternoon, so think I will stick with my current settings for the moment.

Ian.

The slight offset in the curves indicates that your sensor is not quite level.

You will find that the transparency can vary quite a bit, what we think of as clear sunny days are often hazier than you think, particularly if you live near any flight paths. It is very rare nowadays to get the really deep blue skies of 'clear' air.

Thanks, The sensors "seem" level, I did tighten a couple of the screws to get the little bubble level that's on the sensor, but will check again.

Yes, the sky can be quite hazy in London, and I do get planes going over on their approach to Heathrow, so a clear day is often a whitish sky.

Ian.

I have just been outside with a small level, and amended the screws so that the level was level when put on top of the sensor in 2 directions. The little "in-built" bubble level on the sensor is now slightly off (but still within the black ring on it). Also, there is a little "fin" on the sensors to mark North and South, but due to the position of my ISS unit mine are slightly off by maybe 5 degrees, so not sure if that's also affecting the curve.

1. I think you'll find that the trans number which works best at one time of the year won't be the best at another time of year. You already have a very good match.

2. As you've been looking at other posts, I imagine you already know to expect that with broken cloud opportunistic reflections will send some individual data points well above the "maximum", and are not a reason in themselves to "correct" the maximum upward.

archae86 wrote: 2. As you've been looking at other posts, I imagine you already know to expect that with broken cloud opportunistic reflections will send some individual data points well above the "maximum", and are not a reason in themselves to "correct" the maximum upward.

Yes, as proved with todays chart....